hey ya'll, so once again i'm having issues with the eccentric brakes on the rear of my 37 ford panel. for the second time, i've adjusted the brakes using the procedure described in the suggestion provided by the experts in my last post. i have also replaced the wheel cylinders, springs, adjusting cams and anchor pins. the shoes are new but replaced by the previous owner. after both adjustments, i have taken the truck out for a test drive. everything seems fine until about 10 or 15 miles in. after that, i can feel the brakes start to grab. i can hear a rhythm sounding rubbing and by the time i get back and jack the truck up, the rear wheels are locked up and i can't move them. so what's going on? before i throw the towel in and replace them with 39 lincoln type brakes i thought i'd run it by the HAMB experts to see what everyone thinks. some of the things i was thinking are wrong size shoes or drums that are rubbing and causing the shoes to expend because they get so hot. or maybe the drums are hitting the shoes and when the wheels are torqued down they are making contact? any advice would be greatly appreciated.
Do you have clearance between the end of the pedal plunger and your master cylinder? Sounds like it could be holding pressure all the time.
It sounds like deterioration of rubber lines which can prevent the pressure from releasing the brakes
hey guys, thanks for the replies. alchemy, if you mean a distance between where the pedal ends and the master cylinder, yes there is about 6". as for the rubber lines hector, they look pretty new and are still soft but i think i'll replace them just to make sure. thanks again
i forgot to ask if anyone knows, what size the hard lines should be and if that would have any effect? thanks
1: what kind of brakes are on your ford? Stock would have been mechanical so the 1937 ford part doesn’t offer many clues. 2: I had a similar problem and after replacing a hand full of parts we realized I needed a stiffer brake pedal return spring! Problem fixed
No, I mean is there a bit of clearance between the end of the plunger rod down in the master and the piston itself. There needs to be about 1/16” to ***ure you don’t have pressure at all times.
It's called Free Play and do you have a return spring on the pedal to keep it off the piston/plunger.
thanks again for the replies. tim, i think the eccentric brakes are from a 39 - 43 but i guess there is someone out there that can confirm that. i do have a new return spring but i haven't installed it because the old one looked ok but i'll change that as well. as for the free play, i'll check that out and post what i find. cheers!
Ford used 1/4" lines on the Lockheed brake systems. While some say it makes no difference and that pressure will be equal through out with either 3/16" or 1/4" lines; the issue with early Ford brakes is "flow" and 1/4" lines allow proper flow of the larger volume of the Lockheed wheel cylinders during brake release. Your description of the problem sounds like incomplete release of the master cylinder due to insufficient free play or inadequate pedal return spring, as has been well explained in the previous replies.
ok guys, once again thanks for all the replies. as usual, the HAMB has the answers. it turns out that when the previous owner switched to juice brakes it changed the pedals return position in relation to the floor board. when the pedal was in the return position, there was no end play. i discovered this when i took a test ride with the top floor board out. i had already changed the rear line to 1/4", replaced the master cylinder and "tee" and also the return spring. not sure if they needed replacing but at least they are now new but i think it was just the floor board. in any case, i hope this info helps someone out in the future. cheers
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